# CVE-2020-5232: Ethereum Name Service - Malicious takeover of previously owned ENS names

> ENS domain owners can secretly regain ownership of transferred domains, allowing unauthorized control over name resolution.

- **Severity:** High 8.7 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 30 Jan 2020
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-8f9f-pc5v-9r5h

## What is CVE-2020-5232?

CVE-2020-5232 is a high-severity vulnerability in @ensdomains/ens, published on 30 Jan 2020. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

A user who owns an ENS domain can set a trapdoor, allowing them to transfer ownership to another user, and later regain ownership without the new owners consent or awareness. A new ENS deployment is being rolled out that fixes this vulnerability in the ENS registry.

Weakness: CWE-285 (Improper Authorization)

## Which versions are affected by CVE-2020-5232?

2 open source packages ship an affected version, including @ensdomains/ens. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `@ensdomains/ens` | npm | All versions | 0.4.0 |
| `@ensdomains/ens` | npm | All versions | 0.4.0 |

Products: Ens.domains Ethereum Name Service.

## How do I fix CVE-2020-5232?

Upgrade @ensdomains/ens to 0.4.0 or later.

## Is CVE-2020-5232 being exploited?

There is no known exploitation of CVE-2020-5232 in the wild and no public exploit code.

## Other vulnerabilities in @ensdomains/ens

- [CVE-2023-38698](https://insights.sbomify.com/CVE-2023-38698/): .eth registrar controller can shorten the duration of registered names (medium 4.9)
- [CVE-2026-22866](https://insights.sbomify.com/CVE-2026-22866/): ENS DNSSEC Oracle Vulnerable to RSA Signature Forgery via Missing PKCS#1 v1.5 Padding Validation (low 2.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-5232 and fix it if it is affected.

What it is: CVE-2020-5232 is a high-severity vulnerability in @ensdomains/ens, published on 30 Jan 2020. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2020-5232 in the wild and no public exploit code.

Affected packages and fixed versions:
- @ensdomains/ens (npm): affected all versions; fixed in 0.4.0
- @ensdomains/ens (npm): affected all versions; fixed in 0.4.0

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2020-5232/ (Markdown: https://insights.sbomify.com/CVE-2020-5232/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-5232
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-5232
- OSV: https://osv.dev/vulnerability/CVE-2020-5232

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-5232/
Summaries are generated and may contain mistakes; the official description above is the record.